Brush lifting relay mechanism



y 1943- R. M. HEINTZ ET AL, 293247156 BRUSH LIFTING RELAY MECHANISM Filed July 11, 1941 2 Sheets-Sheet l July 13, 1943. R. M. HEINTZ ET AL 2,324,156

BRUSH LIFTING RELAY MECHANISM Filed July 11, 1941 2 Sheets-Sheet 2 ATTORNEYS enema July 13, 1943 BRUSH LIF'I'IN G RELAY MECHANISM Ralph M. Kelli". Shaker Heights, and Philip F.

Sooiield,

ration of Ohio Cleveland H ights Ohio, anignors to Jack a Heints, !nc., Clevelan Application July 11, 1941, Serial No. 402,022

. starter casing 2, enclosing the field windings and 14' Claim.

This invention relates to relays for operating electric motors, and, more particularly, to those adapted for use in high speed motors, such as electric motors for impulse starters of aircraft engines.

Electric motors for impulse starters of this type are generally supplied with power from a battery, and necessarily, the voltage is low, and the current required for starting is high. As a result, contact pressure for the starting of the motor must be high. When the starter contact is made by motor brushes against a commutator, the pressure required is comparatively light, and

thus, less energy is necessary to operate the relay.

The desirability of accomplishing starting of motor for impulse starters by brush contact is seen to be obvious, and, therefore, the present relay has been devised to effect this in a novel and eiilcient manner, and an object of this invention is to provide positive yieldable contact means for the brushes.

Another object of this invention is to provide a compact brush actuating unit that is easily assembled in the motor housing, and readily removable therefrom.

A still further object of this invention is to provide rapidly acting mechanism affording the contact of the brushes with the commutator.

Still another object of this invention is to provide a novel form of brush retracting linkage.

Further objects and advantages will be apparent from reference to the following description and attached drawings.

In the drawings- Figure l is an end view of the commutator housing shown mounted on a motor and the general location of the brush actuating unit therein.

Figure 2 is a side view partly in section, showing the commutator, part of the armature and certain details of the actuating mechanism taken about on the line 2-2 of Figure 1.

Figure 3 is a detail side view of the brush actuating unit.

Figure 4 is a detail section view of part of the brush actuating unit about on the line H 'of Figure 3.

Figure 5 is a top view of certain parts of the actuating unit showing the arrangement of the toggle connections with certain parts broken away, this view being taken on the line 5-5 of Figure 3.

The description of the parts of the brush actuating mechanism, and associated mechanism,

shown is a follows:

A motor casing i is shown as mounted on a core, which are not shown in detail, as they may be of well known conventional form where used in connection with this invention.

An armature 3 is also generally shown, and may be a standard type. A commutator 4 of the armature, the shaft 5, and the bearings 6, are shown in connection with the armature, and furnished with a conventional bearing retaining collar 1.

A casing 8, around the end of the commutator 4, and housing the commutator and adapted to support the bearings 6, in which the armature shaft 5 rotates, is shown generally in Figure 2. A cover plate 9, suitably fastened to the casing 8 by means of bolts Iii, and likewise, a cap ii suitably held by bolts i2 over the end of the armature shaft, complete the end closure of the motor and housing.

Adapted to be inserted through a rectangular opening I 3 in the casing 8, is the brush lifting and relay unit It, shown in detail in Figure 3, and held in engagement with the casing 8 by means of bolts i5 suitably threaded in the casing, which fasten the base plate i6 thereto.

The brush lifting and relay unit It comprises contact bearing arms ll, of suitable material, and of substantially U-shaped configuration throughout their length, having the contact members I8, which, for the purposes of this invention, may be generally round rod-like members fastened at one end by suitable means, on an angular portion IQ, of the contact bearing arms 11, said arms secured at their other ends to angular insulating members 20, by suitable means 2i, the insulating members 20 in turn being suitably fastened to the base plate It by means of bolts 22. Near the contact bearing portions is of the contact arms I! are formed suitable lugs or cars 23, on which are pivoted the ends 24 of the brush holders 25. by means of pivots 2B engaged with the lugs or ears 22. The brush holders 25 are right and left hand parts, as shown in Figure 4, and are pivotally mounted in pairs on the pivots 2G.

The brush holders 2! are formed at the ends opposite the pivot bearing portions 24 with substantially U-shaped brush receiving portions 21 adapted to suitably clamplngly engage brushes 28 held therein by means of bolts 2!.

Formed adjacent the U-shaped brush holding portions 21 of the brush holders 25 are suitable lugs 28 adapted to engage insulating rollers 30. of a brush retracting toggle unit, in a manner to be later set forth.

Positive electrical contact of the brushes 28 with the contact members id'is effected by means of conventional pigtails 8i suitably fastened to the contact members it by rivet portions 32 formed thereon and burrs 33, which likewise rigidly secure the contact members i8 to the contact bearing portions it of the contact arms ii, and at their other ends, thepigtails it are secured to the bottoms 3d of the U-shaped brush holding portions 2? of the brush holders 25 by suitable means.

Leaf springs 35 fastened to the arms of the I brush holders 25, in a conventional manner, pass over the pivot portions 23 of the brush holders 25, and engage pins 36, to resiliently hold the brushes 28 in contact with the commutator t. the pins 36 being suitably fastened between the ears or lugs 37 of the contact arms ll, when permitted to do so upon actuation of a cylindrical plunger 38a of a magnet coil or solenoid 38, which is supported on the base plate it, through the means now to be described.

A fixed core 39 is secured in the outer end of the solenoid 38, and has a generally conical face 39a having a counter-bore at, substantially centrally thereof, adapted to receive a suitable compression spring A i, said compression spring seated in contact with a shell 380 of the coil 38. The plunger 380; is slidably mounted in the solenoid 38 and has a concave conical surface 382) to cooperate with the convex conical surface 39a oi the stationary core 39.

The plunger 3% is likewise provided with a counter-bore 52, which is adapted to receive the other end of the compression spring at, said compression spring normally maintaining the plunger 38a separated from the stationary core 39. A sleeve 53, suitably fastened in the coil 38 by engagement of a shoulder portion 3312 within the shell member 38d of the solenoid 38, and enclosing a, thin tubular guide sleeve 6% in which the plunger 38a is slidably mounted, is provided with ears it at its end, adapted to support ends of toggle links (it on the pivot dd, which may be a rivet of conventional form, as shown in Figure 5.

Suitable spacers ill on the pivot 56 maintain the toggle links 55 substantially centrally thereof, and act as limiting means for movement of the plunger 38a upon expansion of the spring ti the plunger 38a having shallow slots 38c so positioned as to be engaged by the spacers @i when the plunger 38a is in full brush retracting position.

Interleaved with and connected substantially centrally their ends with the divergent toggle links 35 on the pivots 35a, are toggle levers Qt, having the aforementioned rollers 30 mounted at their extremities on shafts 85a in position for contact with the previously mentioned ears Or lugs 29 of the brush holders 25, and at their inner ends connected to each other on a Divot 380., said inner connected ends being slidable in a slot 33] cut in the sliding core 38a, as generally indicated in Figures 3 and 5, and seated on the bottom of the slot.

Thus, what may be generally termed a separating action of the insulating rollers as on the ends of the levers 63, is imparted thereto, when the compression spring 6i expands after de-energization of the solenoid 38. This toggle connection is seen to ailord an equal movement of the insulating rollers 30 and thus imparts an equal movement to the brush holders engaged thereby and the brushes mounted in the brush holders, as before described. It is likewise seen that a relatively small movement of the s in core 38a is seen to provide a relatively great move ment of the rollers St on the links 58 and thus provide a compact actuating linkage.

The brush lifting relay unit id, is positively connected in the motor operation circuit by in sertion of the contact members it in posts is, which are mounted in the shell 8 of the commutator housing, and are suitably held in engagement therewith by means of nuts 58 screwed on threads of the posts 59 against collars 58, which collars engage the contact members it. The posts 39 are suitably connected in the operating circuit in a conventional manner, not shown. This manner of electrically connecting the unit it in the motor circuit provides easy removal and replacement of the brush lifting and relay unit in a novel manner.

The operation of the mechanism of the brush lifting relay unit it is more readily understood from a description of the motion of the parts comprising the same, and is as follows:

To properly place the brush lifting relay unit it in position within the commutator housing a, the unit as a whole is inserted in the previously mentioned rectangular opening 53, with the contact members It engaged in the openings of the posts at, and, thereafter, the bolts i5 are screwed through the base plate it of the unit 9 1, and from this point, the actual operation of the unit will be described:

With the brushes 28 out of contact with the commutator #3, as shown in Figure 3, under the normal condition where the electric motor in which the brush lifting relay has been incorporated is not in motion, a circuit, not shown, is closed, and the solenoid unit 33 energized. Thereupon, the plunger 38a is attracted to the stationary plunger 39 with enough force to overcome the tension of the compression spring 48. The ends of the toggle levers $8 on which the insulating rollers 39 are mounted will move relatively toward one another, and permit the brushes 28 to come into contact at the same instant with the commutator 6, since the leaf springs 35, through the means previously mentioned, tend to move the pivoted brush carrying members 25 toward the commutator. Starting contact for the motor is completed thereby and the armature set into motion. .At the same time that the brush carrying members 25 move toward the commutator, the lugs 2Q, associated therewith, carry with them the insulating rollers 38 and move the levers 58, as previously described. Movement of the brushes 28, as wear occurs, will be possible, since there is no limiting means for contact movement of the arms 25, except when the brushes have been worn out completely.

From the foregoing, it will be seen that upon de-energization of the solenoid 38, the compres sion spring M will expand tending to force the slidable plunger 38a away from the stationary plunger 39, and acting upon the toggle links and levers Q5 and d8, retract the brushes from contact with the commutator through the means previously mentioned against the unfolding tension of the springs 35, and permit the armature to slow down.

The electrical circuits in themselves are not generally shown or described in this application, in view of the fact that they will be readily understood by those skilled in the art, and are not necessarily of any particular diflerent arrangement in respect to the invention disclosed herein.

Having thus described our inventiom what we clam as new and desire to secure ent of the United States is:

1. In brush operating mechanism of the class described, in combination, a commutator, a brush lifting and relay unit associated with the commutator and comprising a plurality of brush carrying members, means pivotally supporting said brush carrying members at corresponding ends thereof, brushes mounted on the brush carrying members to coact with the commutator, means normally tending to move said brush carrying members for effecting contact of the brushes with the commutator, retracting means for lifting the brushes away from the commutator, including a toggle unit comprising toggle levers engaging the brush carrying members, instrumentalities supporting the ggle levers, and means for actuating the toggle levers simultaneously for causing the portions thereof engaging the brush carrying members to simultaneously effect movement of the latter. I

2. A brush operating mechanism as set forth in claim 1, combined with insulating rollers carried by the toggle levers for effecting their movement with the brush carrying members, toggle links connected to the toggle levers intermediate the ends of the latter, and pivot means supporting and connecting adjacent ends of the toggle links.

3. A brush lifting and relay mechanism as claimed in claim 1, in which the means for operating the toggle levers comprises a solenoid plunger adapted to move the toggle levers to lift the brushes away from the commutator against the action of the means normally tending to move said brushes into contact with the commutator, and means to energize said solenoid plunger whereby to relieve the toggle levers of the action of the plunger for effecting contact of the brushes with the commutator.

4. A brush lifting and relay mechanism, as claimed in claim 1, wherein the brush carrying members are disposed in spaced pairs, the members of each pair being disposed side by side and adapted for independent movement.

5. A brush lifting and relay unit mechanism, as set forth in claim 1, combined with contact rollers at the outer or free ends of the toggle by Letters Pat- I levers, the brush carrying members having contact lugs offstanding from their free ends, and engaged with the said rollers of the toggle levers.

6. A brush lifting and relay mechanism comprising in combination, a commutator, a brush carrying and operating unit comprising a base plate, spaced arms projecting from said base plate, terminal members carried by said spaced arms for engaging contact posts for establishing electrical contact'with the latter and supporting said unit removably associated with said posts. and brush supporting and operating devices carried by said brush carrying and operating unit.

, 7. A brush lifting and relay mechanism, as

claimed in claim 6, in which the brush carrying and operating devices are interposed between the spaced arms supported on the base plate.

8. A brush lifting and relay mechanism, as claimed in claim 6, in which the brush carrying and operating devices are interposed between the spaced arms supported on the base plate, the brush ca rying devices comprising brush supporting arms plvotally disposed at opposite portions of the commutator, brushe on said arms movable toward and from the commutator, and a toggle device interposed between the brush carrying arms cooperatively engaging the same to move the said arms outwardly from the commutator to lift the brushes from the latter.

9. A brush lifting and relay mechanism, as claimed in claim 6, in which the brush carrying and operating devices are interposed between the spaced arms supported on the base plate, the brush carrying devices comprising brush supporting arms pivotally disposed at opposite portions of the commutator, brushes on said arms movable toward and from the commutator, and a toggle device interposed between the brush carrying arms cooperatively engaging the same to move the said arms outwardly from the commutator to lift the brushes from the latter, said toggle device comprising pivotally connected toggle levers, rollers on the free ends of said levers for establishing engagement thereof with the brush carrying arms, toggle links supported by the base plate pivotally connected together at adjacent ends and having their opposite ends pivotally connected with the toggle levers intermediate the ends of the latter.

10. In a brush lifting and relay mechanism, in combination, a commutator, a brush carrying and operating unit comprising a base plate, spaced arms projecting from the base plate. brush carrying arms pivoted to said spaced arms, brushes on the brush carrying arms movable toward and from the commutator, the brush carrying arms being disposed adjacent to opposite sides of the commutator, a toggle unit interposed between the brush carrying arms and comprising toggle levers engaging at their outer ends said brush carrying arms for eflectlng movement of the latter, and actuating means for said toggle levers for simultaneously moving the same and correspondingly effecting movement of the brush carrying arms.

11. A brush lifting and relay mechanism comprising in combination, a commutator, pairs of brush carrying arms associated with said commutator, brushes carried by said arms for cooperation with the commutator, the arms of each pair aforesaid being disposed side by side, means for independently effecting movement of the arms in relation to the commutator, and operating instrumentalities arranged between the pairs of brush carrying arms forsimultaneous actuation thereof, said operating instrumentalities comprising a toggle lever unit interposed between the pairs of brush carrying arms and including toggle levers, rollers on the outer ends of said toggle levers coacting with the brush carrying arms, and a plunger arranged to actuate the toggle levers at their inner ends for effecting simultaneous movement thereof.

12. A removable brush carrying unit for electric motors and the like having commutators, said unit comprising a base plate, spaced arms projecting from said base plate, terminal members carried by said spaced arms for supporting said unit removably associated with contact posts in a motor, brush supporting devices carried by said arms and containing brushes, and brush retracting means carried by said base plate, said terminal members establishing circuits to said brushes and accurately positioning said arms for the proper relation of said brushes with respect to the commutator of a motor to which the unit is applied.

13. A removable brush carrying unit for electric motors and the like having commutators, said unit comprising means for holding a pair of retractable brushes in predetermined relations to a commutator, means for causing said brushes to bear against said commutator in open ative relation therewith, means for retracting said brushes from contact with said commutator,

mutator, means for causing said brushes to bear against said commutator in operative relation therewith, means for retracting said brushes from contact with said commutator, and means for automatically establishing circuits to said brushes and accurately positioning said unit when applied to a motor, said unit including all of said means being thereby adapted to be readily applied to or removed from said electric motor 10 or the like. 

